Versatile Supramolecular Gelators That Can Harden Water, Organic Solvents and Ionic Liquids

摘要

We developed novel supramolecular gelators withnsimple molecular structures that could harden a broad range ofnsolvents: aqueous solutions of a wide pH range, organic solvents,nedible oil, biodiesel, and ionic liquids at gelation concentrations ofn0.1−2 wt %. The supramolecular gelators were composed of anlong hydrophobic tail, amino acids and gluconic acid, which werenprepared by liquid-phase synthesis. Among seven types of thengelators synthesized, the gelators containing L-Val, L-Leu, and L-Ilenexhibited high gelation ability to various solvents. These gelatorsnwere soluble in aqueous and organic solvents, and also in ionic liquids at high temperature. The gelation of these solvents wasnthermally reversible. The microscopic observations (TEM, SEM, and CLSM) and small-angle X-ray scattering (SAXS)nmeasurements suggested that the gelator molecules self-assembled to form entangled nanofibers in a large variety of solvents,nresulting in the gelation of these solvents. Molecular mechanics and density functional theory (DFT) calculations indicated thenpossible molecular packing of the gelator in the nanofibers. Interestingly, the gelation of an ionic liquid by our gelator did notnaffect the ionic conductivity of the ionic liquid, which would provide an advantage to electrochemical applications.